The present invention relates to a catalyst support. More particularly, the present disclosure relates to a high surface area catalyst support for use, for example, in a fuel cell.
Electrodes containing supported metal catalyst particles are used in electrochemical cells, such as fuel cells. For example, in a conventional hydrogen fuel cell, a supported platinum catalyst is used to oxidize hydrogen gas into protons and electrons at the anode of the fuel cell. At the cathode of the fuel cell, another supported platinum catalyst triggers an oxygen reduction reaction (ORR), leading to the formation of water.
The catalyst support is typically a conductive high surface area carbon. The catalyst support provides a surface over which the catalyst particles are dispersed and stabilized. However, carbon catalyst supports in fuel cells are susceptible to corrosion that results in carbon oxidation and, as a final stage, collapse of the carbon structure. Causes of corrosion include the presence of oxygen, water, and high electrode potential, especially on the cathode side. Additionally, mixed potential resulting from the electrochemical reaction may exist locally. Corrosion causes microstructural derogation and surface chemistry changes, which may result in an irreversible loss in catalytic performance, cross-over and ultimately in the complete failure of the fuel cell.
Additionally, the carbon support may have poor interactions with the catalyst particles, which results in electrode changes, and more specifically, particle growth of catalyst particle sizes under dissolution/redeposition processes. The increase in size of the catalyst particles through dissolution/redeposition causes a loss in fuel cell performance. An improve catalyst support that resists corrosion is needed so that the performance of an electrochemical cell can be maintained.